Soil properties vary in space even within a soil layer. Nevertheless, site response analyses are typically conducted using a best-characterized shear wave velocity (Vs) profile without considering its fluctuation. In this study, the random field theory is adopted to model heterogeneous Vs profiles for a range of coefficient of variations (COVs) and correlation lengths (CLs). Linear 1D site responses are analyzed with the randomized profiles to quantify the influence of spatial Vs variation on the propagated ground motions. Results reveal that a higher COV of randomized Vs profiles leads to a lower mean ground response compared with a homogeneous Vs profile. The variation of CL does not significantly affect the surface response and peak ground acceleration profile, but is shown to influence the degree of fluctuation of the maximum shear strain profiles. For idealized profiles, the effect of heterogeneous Vs on ground response can be approximately predicted by using reduced Vs and enlarged small strain damping that are dependent on COV.

即使在土壤层内，土壤性质在空间上也不同。然而，场地响应分析通常使用最佳表征的横波速度 (Vs) 剖面进行，而不考虑其波动。在本研究中，采用随机场理论对一系列变异系数 (COV) 和相关长度 (CL) 的异质 Vs 剖面进行建模。使用随机剖面分析线性 1D 场地响应，以量化空间 Vs 变化对传播的地面运动的影响。结果表明，与均匀的 Vs 剖面相比，随机 Vs 剖面的较高 COV 导致较低的平均地面响应。CL 的变化不会显着影响表面响应和峰值地面加速度剖面，但显示会影响最大剪切应变分布的波动程度。对于理想化的剖面，通过使用依赖于 COV 的减小的 Vs 和扩大的小应变阻尼，可以大致预测非均质 Vs 对地面响应的影响。